They have just reported that according to their sources, the investigation into Russian collusion has identified a current White House official as "a significant person of interest," thus expanding the probe into the highest levels of government.

The person under scrutiny is someone close to the president, according to the sources, who would not identify the official.

Investigators are apparently shifting from work that has remained under the radar to conducting interviews and using a grand jury to issue subpoenas. The Post sources say the intensity of the probe is "expected to accelerate" in the coming weeks.

The sources emphasized that investigators remain keenly interested in people who previously wielded influence in the Trump campaign and administration but are no longer part of it, including former national security adviser Michael Flynn and former campaign chairman Paul Manafort.

WASHINGTON - President Trump told Russian officials in the Oval Office this month that firing the F.B.I. director, James B. Comey, had relieved "great pressure" on him, according to a document summarizing the meeting.

"I just fired the head of the F.B.I. He was crazy, a real nut job," Mr. Trump said, according to the document, which was read to The New York Times by an American official. "I faced great pressure because of Russia. That's taken off."